The present disclosure relates to network computing. Computer networks typically include a collection of computing devices enabled to communicate with each other for handling data traffic and control instructions. For example, such devices can include servers, data centers, routers, network switches, management applications, wireless access points, and client computers. Computer networks can provide network connectivity to wired computing devices and/or wireless computing devices.
One type of network technology is known as Shortest Path Bridging (SPB). A set of standards for implementing Shortest Path Bridging is generally specified by the Institute of Electrical and Electronics Engineers (IEEE). Specifically, this standard is identified as IEEE 802.1aq. Network services, including SPB services are commonly provided using Ethernet technology. Ethernet has become a default Data Link Layer technology for data transport, that is, the default for Layer 2 (L2) of the Open Systems Interconnection (OSI) model. SPB can expand Ethernet technologies to other or larger networks. For example, a network that uses IEEE 802.1aq SPB can advertise both topology and logical network membership. SPB uses a link state protocol for such advertising.
In an SPB network, packets are encapsulated at an edge node either in Mac-in-Mac 802.1ah or Q-in-Q 802.1ad frames and transported only to other members of the logical network. IEEE 802.1aq supports unicast and multicast, and all routing is on symmetric shortest paths. IEEE 802.1aq includes Shortest Path Bridging MAC (SPBM) functionality. There exist other related technologies that follow the model of a provider network (transport network) that connects two or more customer networks (access networks), where the provider network is functionally distinct from the customer network, even if a single administrator runs both networks.
For example, one technology is Provider Backbone Bridges (PBB) technology. A PBB network is a L2-Bridged network that uses Mac-In-Mac encapsulation to transfer user L2 traffic between two or more L2 networks that are located at the edge of the PBB network (provider network). Note that a PBB network includes all networks that use Mac-In-Mac encapsulation technology, including, but not limited to, networks that use the Shortest Path Bridging Technology commonly referred to as SPB or SPBV or SPBM. The PBB network typically includes a Backbone Edge Bridge (BEB) and a Backbone Core Bridge (BCB). BEBs (also known as provider network edge nodes) function as devices that enable transfer of packets to/from interfaces within the PBB network and to/from interfaces outside the PBB network. BCBs (also known as provider core nodes) enable transfer of packets between interfaces that are within the PBB network. Sender BEBs are also known as Ingress BEBs, while receiver BEBs are also known as Egress BEBs.
A network protocol related to SPB is known as Intermediate System To Intermediate System (IS-IS). IS-IS is a routing protocol that routes data by determining a best route for datagrams transmitted through a packet-switched network. The IS-IS protocol is published by Internet Engineering Task Force (IETF) as an Internet Standard in RFC 1142, as well as in International Organization for Standardization (ISO)/International Electrotechnical Commission (IEC) 10589: 2002. SPB Networks can use IS-IS as a control protocol and type-length-value (TLV) structures for control messaging. A TLV structure allows optional information to be encoded within a given packet.